Gilbert's syndrome--a legitimate genetic anomaly?

Primary myelofibrosis with thrombophilia as first symptom combined with thalassemia and Gilbert syndrome: A case report

BACKGROUND

A 46-year-old Han man first had sigmoid sinus and transverse sinus venous thrombosis at the age of 42. At the age of 44, he once again developed thrombosis. Genetic testing showed heterozygous SERPINC1 mutation, bone marrow biopsy showed fibrosis grade 1 (MF-1), and JAK2 V617F mutation was positive, accompanied by UGT1A1 mutation and β-thalassemia gene mutation.

CASE SUMMARY

A 46-year-old Han man was first found to have sigmoid sinus and transverse sinus venous thrombosis at the age of 42 but had no individual or family thrombosis history, and he had been regularly taking warfarin anticoagulant therapy for a long period of time. At the age of 44, venous thrombosis reappeared in parts of the intrahepatic vein, main portal vein, splenic vein, and superior mesenteric vein, and his spleen was obviously enlarged. He had a history of jaundice for many years, and genetic testing revealed that he carried a heterozygous SERPINC1 mutation. Bone marrow biopsy showed multifocal fibrous tissue hyperplasia among trabeculae and focal fibrosis. He was positive for the JAK2 V617F mutation. At the same time, UGT1A1 and β-thalassemia gene mutations existed, and a SERPINC1 mutation and UGT1A1 mutation were both found in his parents.

CONCLUSION

The patient in this case had thrombophilia as the primary symptom, JAK2V617-positive myeloproliferative neoplasm (MPN) was the main potential cause, and hereditary AT-III deficiency may have been one of multiple secondary causes. It remains to be determined whether UGT1A1 and β-thalassemia gene mutations are related to thrombophilia. However, the clinical features of MPN in this patient were hidden, and the relevant clinical features of coexisting thalassemia and hereditary Gilbert syndrome, reported here for the first time domestically and abroad, were complicating factors, causing great difficulties for a clear diagnosis. Thus, when thrombophilia has been determined, it is necessary to screen the relevant latent problems overall. When the clinical features cannot be perfectly explained by one etiology, a relevant comprehensive examination should also be initiated from the perspective of multiple etiologies.

Increased subsequent risk of inflammatory bowel disease association in patients with chronic pancreatitis: a nationwide population-based cohort study

PURPOSE

To investigate the relationship between chronic pancreatitis (CP) and inflammatory bowel disease (IBD) in a large population-based cohort study.

METHODS

Data was obtained from the Taiwan National Health Insurance Research Database. The cohort study comprised 17,796 patients newly diagnosed with CP between 2000 and 2010 and 71,164 matched controls. A Cox proportional hazards model was used for evaluating the risk of IBD in the CP and comparison cohorts.

RESULTS

When examined with a mean follow-up period of 4.87 and 6.04 years for the CP and comparison cohorts, respectively, the overall incidence of IBD was 10.3 times higher in the CP cohort than in the comparison cohort (5.75 vs. 0.56 per 10,000 person-years). Compared with the comparison cohort, the CP cohort exhibited a higher risk of IBD, irrespective of age, sex, and presence or absence of comorbidities. Moreover, the CP cohort was associated with a significantly higher risk of Crohn's disease (adjusted hazard ratio [aHR] = 12.9, 95% confidence interval [CI] = 5.15-32.5) and ulcerative colitis (aHR = 2.80, 95% CI = 1.00-7.86).

CONCLUSIONS

This nationwide population-based cohort study revealed a significantly higher risk of IBD in patients with CP compared with control group. Clinicians should notice this association to avoid delayed diagnosis of IBD in patients with CP.

New insights in bilirubin metabolism and their clinical implications

Bilirubin, a major end product of heme breakdown, is an important constituent of bile, responsible for its characteristic colour. Over recent decades, our understanding of bilirubin metabolism has expanded along with the processes of elimination of other endogenous and exogenous anionic substrates, mediated by the action of multiple transport systems at the sinusoidal and canalicular membrane of hepatocytes. Several inherited disorders characterised by impaired bilirubin conjugation (Crigler-Najjar syndrome type I and type II, Gilbert syndrome) or transport (Dubin-Johnson and Rotor syndrome) result in various degrees of hyperbilirubinemia of either the predominantly unconjugated or predominantly conjugated type. Moreover, disrupted regulation of hepatobiliary transport systems can explain jaundice in many acquired liver disorders. In this review, we discuss the recent data on liver bilirubin handling based on the discovery of the molecular basis of Rotor syndrome. The data show that a substantial fraction of bilirubin conjugates is primarily secreted by MRP3 at the sinusoidal membrane into the blood, from where they are subsequently reuptaken by sinusoidal membrane-bound organic anion transporting polypeptides OATP1B1 and OATP1B3. OATP1B proteins are also responsible for liver clearance of bilirubin conjugated in splanchnic organs, such as the intestine and kidney, and for a number of endogenous compounds, xenobiotics and drugs. Absence of one or both OATP1B proteins thus may have serious impact on toxicity of commonly used drugs cleared by this system such as statins, sartans, methotrexate or rifampicin. The liver-blood cycling of conjugated bilirubin is impaired in cholestatic and parenchymal liver diseases and this impairment most likely contributes to jaundice accompanying these disorders.

Gilbert syndrome

Gilbert syndrome is a common autosomal dominant hereditary condition with incomplete penetrance and characterized by intermittent unconjugated hyperbilirubinemia in the absence of hepatocellular disease or hemolysis. In patients with Gilbert syndrome, uridine diphosphate-glucuronyl transferase activity is reduced to 30% of the normal, resulting in indirect hyperbilirubinemia. In its typical form, hyperbilirubinemia is first noticed as intermittent mild jaundice in adolescence. However, Gilbert syndrome in combination with other prevailing conditions such as breast feeding, G-6-PD deficiency, thalassemia, spherocytosis, or cystic fibrosis may potentiate severe hyperbilirubinemia and/or cholelithiasis. It may also reduce plasma oxidation, and it may also affect drug metabolism. Although in general the diagnosis of the syndrome is one of exclusion, molecular genetic tests can now be performed when there is a diagnostic problem. The most common genotype of Gilbert syndrome is the homozygous polymorphism A(TA)7TAA in the promoter of the gene for UDP-glucuronosyltransferase 1A1 (UGT1A1), which is a TA insertion into the promoter designated UGT1A1*28. No specific management is necessary as Gilbert syndrome is a benign condition.

CONCLUSION

Gilbert genotype should be kept in the clinician's mind, at least as a contributor factor, in cases with unexplained indirect hyperbilirubinemia.

DNA dynamics is likely to be a factor in the genomic nucleotide repeats expansions related to diseases

Trinucleotide repeats sequences (TRS) represent a common type of genomic DNA motif whose expansion is associated with a large number of human diseases. The driving molecular mechanisms of the TRS ongoing dynamic expansion across generations and within tissues and its influence on genomic DNA functions are not well understood. Here we report results for a novel and notable collective breathing behavior of genomic DNA of tandem TRS, leading to propensity for large local DNA transient openings at physiological temperature. Our Langevin molecular dynamics (LMD) and Markov Chain Monte Carlo (MCMC) simulations demonstrate that the patterns of openings of various TRSs depend specifically on their length. The collective propensity for DNA strand separation of repeated sequences serves as a precursor for outsized intermediate bubble states independently of the G/C-content. We report that repeats have the potential to interfere with the binding of transcription factors to their consensus sequence by altered DNA breathing dynamics in proximity of the binding sites. These observations might influence ongoing attempts to use LMD and MCMC simulations for TRS–related modeling of genomic DNA functionality in elucidating the common denominators of the dynamic TRS expansion mutation with potential therapeutic applications.

Rabdomiólise após exercício físico não intenso

Discutiremos um raro caso clínico de rabdomiólise ocorrido após um exercício físico habitual e não intenso, em paciente masculino de 34 anos e os prováveis fatores desencadeantes envolvidos, bem como suas implicações clínicas. Destacando-se a elevação expressiva e não vista em outros trabalhos como da creatinoquinase, enzimas hepáticas, e as medidas clínicas adotadas para a prevenção de complicações renais sérias e com risco grave para o paciente em análise.

Gilbert syndrome

Az ismert familiáris, nem konjugált hyperbilirubinaemiák közé tartozó Gilbert-szindróma az átlagpopuláció 7–10%-át érintő benignus kórkép. Tünetei rendszerint aspecifikusak, egyedül az esetlegesen előforduló sárgaság, továbbá az enyhén emelkedett nem konjugált bilirubin szintje utal a rendellenességre. Más laborértékek és a májbiopszia általában nem mutat eltérést a normálistól. A betegség hátterében a legtöbb esetben az UDP-glükuronil-transzferáz gén részleges működészavara áll. A gén azt az enzimet kódolja, amely a bilirubin glükuronsavval való konjugációját segíti. Noha a Gilbert-szindróma diagnosztizálása korábban hagyományos laboratóriumi módszerekkel és családi anamnézis felvételével történt, napjainkban lehetőség van az UDP-glükuronil-transzferáz gén genetikai variánsainak meghatározására. A gén promoterrégiójában, homozigóta formában lévő (TA)-inszerció – (TA)7/(TA)7– a betegek 80–100%-ában jelen van, és az aktív UDP-glükuronil-transzferáz mennyiségének csökkenéséhez vezet. A kódolórégióban található missense mutációk szerepe még nem teljesen tisztázott, de a (TA)7promotervariánssal való együttes előfordulásuk magyarázatul szolgálhat az emelkedett bilirubinszintre és a sárgaságra, valamint a Gilbert-szindróma családi halmozódására.

Mononuclear cells modulate the activity of pancreatic stellate cells which in turn promote fibrosis and inflammation in chronic pancreatitis

Background

Interactions between mononuclear cells and activated pancreatic myofibroblasts (pancreatic stellate cells; PSC) may contribute to inflammation and fibrosis in chronic pancreatitis (CP).

Methods

Markers of fibrosis and inflammation were concomitantly analysed by immunohistochemistry in chronic pancreatitis tissues. In vitro, PSC were stimulated with TNFalpha and LPS. Primary human blood mononuclear cells (PBMC) and PSC were cocultured, followed by analysis of cytokines and extracellular matrix (ECM) proteins. PBMC were derived from healthy donors and CP and septic shock patients.

Results

In areas of mononuclear cell infiltration in chronic pancreatitis tissues, there was decreased immunoreactivity for collagen1 and fibronectin, in contrast to areas with sparse mononuclear cells, although PSC were detectable in both areas. LPS and TNFalpha induced collagen1 and fibronectin levels as well as the matrix degradation enzyme MMP-1. Coculture experiments with PSC and PBMC revealed increased fibronectin secretion induced by PBMC. In addition, donor and CP PBMC significantly induced an increase in IL-6, MCP-1 and TGFbeta levels under coculture conditions. Determination of the source of cytokines and ECM proteins by mRNA expression analysis confirmed PSC as major contributors of ECM production. The increase in cytokine expression was PBMC- and also PSC-derived.

Conclusion

Mononuclear cells modulate the activity of pancreatic stellate cells, which may in turn promote fibrosis and inflammation.

UGT1A1 promoter genotype correlates with SN-38 pharmacokinetics, but not severe toxicity in patients receiving low-dose irinotecan

PURPOSE

To study the association between UDP-glucuronosyltransferase 1A1 (UGT1A1) genotypes and severe toxicity as well as irinotecan disposition in pediatric patients with solid tumors receiving low-dose, protracted irinotecan (15 to 75 mg/m2 daily for 5 days for 2 consecutive weeks).

PATIENTS AND METHODS

Seventy-four patients on five institutional clinical trials received irinotecan (15 to 75 mg/m2) daily intravenously or orally for 5 days for 2 consecutive weeks. Genomic DNA was genotyped for UGT1A1*28, and patients were designated as 6/6, 6/7, or 7/7 depending on the number of TA repeats in the UGT1A1 promoter region. Patients were evaluated for gastrointestinal and hematologic toxicity, as well as baseline and maximal serum bilirubin levels. Toxicity and pharmacokinetic results were evaluated during courses 1 and 2 of irinotecan therapy.

RESULTS

The frequencies of 6/6, 6/7, and 7/7 genotypes were 27 (36.5%), 36 (48.6%), and 9 (12.2%) of 74 patients, respectively. Patients with 7/7 genotype had a statistically greater baseline total bilirubin than patients with 6/6 or 6/7 genotype (P = .005). UGT1A1*28 genotype was not associated with grade 3 and 4 neutropenia (P = .21 for course 1; P = .23 for course 2) or diarrhea (P = .176 for course 1; P = .87 for course 2). However, patients with the 7/7 genotype tended to have higher SN-38 area under the plasma time-concentration curve (AUC) values and lower SN-38G/SN-38 AUC ratios.

CONCLUSION

Severe toxicity was not increased in pediatric patients with the 7/7 genotype when treated with a low-dose protracted schedule of irinotecan. Therefore, UGT1A1 genotyping is not a useful prognostic indicator of severe toxicity for patients treated with this irinotecan dosage and schedule.

Inheritance of hyperbilirubinemia: evidence for a major autosomal recessive gene

BACKGROUND AND AIM

To clarify the precise mode of inheritance of Gilbert syndrome, an unconjugated familial hyperbilirubinemia, where impaired bilirubin conjugation is caused by reduced UGT1A1 activity determined by a defective function of the A(TA)6TAA promoter region of the UGT1A1 gene.

SUBJECTS AND METHODS

Serum bilirubin levels were measured in a large, homogeneous resident population from North-Eastern Italy, consisting of 1.639 males (age 44.5+/-13.9, range 18-89 years), and 1.420 females (age 45.1+/-15.0, range 18-85). In 112 nuclear families from hyperbilirubinemic probands living in the same area a complex segregation analysis was then performed. In both samples we carefully excluded potentially confounding factors of bilirubin levels (alcohol abuse, excessive cigarette smoking, drug consumption, overt haemolysis and liver disease).

RESULTS

Mean serum bilirubin concentrations are higher in males than in females, showing fluctuations through the different age periods in males. Complex segregation results demonstrate that unconjugated hyperbilirubinemia exhibits a precise mode of inheritance in which a major recessive gene with a frequency of 0.45 is responsible for higher serum bilirubin values.

CONCLUSIONS

This major recessive gene accounts only for a part of the serum bilirubin concentration, thus implying additional, environmental factors for the clinical appearance of GS.

Gilbert’s syndrome in children: Our experience

Introduction: Gilbert?s syndrome represents the most frequent hereditary disorder of bilirubin metabolism. It occurs in 2-7% of subjects in general population, and is manifested by mild unconjugated hyperbilirubinaemia of benign nature. Objective. The study was conducted in order to analyse our experience related to the circumstances of disclosure, age at onset and sex distribution of Gilbert?s syndrome in children. Method. The diagnosis of Gilbert?s syndrome was based on the findings of mild unconjugated hyperbilirubinaemia in the absence of haemolysis and organic liver disease, as well as significant increase of bilirubin unconjugated fraction in serum after a 3-day hypocaloric diet (400 kcal/daily). Results. Of 58 subjects with Gilbert?s syndrome, there were 40 (68.97%) boys and 18 (31.03%) girls, indicating a 2.22 fold higher incidence of boys than girls. The age at diagnosis of the disorder was similar in boys and girls, and was 12.2-18 (X=14.71?1.55) years for boys and 10.5-16.4 (X=14.38?2.10) years for girls (p>0.05). Except for 3 girls aged below 12 years, in all other patients the diagnosis was made after that age; in 20, between age 12 and 14 years and in 14, between age 14 and 16 years, while in 10 patents, it was made at age between 16 and 18 years. In 20 (34.48%) subjects, hyperbilirubinaemia was disclosed on routine paediatric examination, in 19 (32.76%) when differentiating the cause of recurrent or acute abdominal pain, in 17 (29.3%) during febrile condition and in 2 during insufficient caloric intake. The values of unconjugated bilirubinaemia, both before a hypocaloric test and after a 3-day energy deprivation, were higher in boys than girls, but this difference was statistically significant only after the 3-day hypocaloric diet in age group between 16 and 18 years (p=0.038). Also, no significant difference was found in bilirubinaemia level between the different age groups either in boys or girls. Conclusion. According to our findings, in children, Gilbert?s syndrome is manifested only in puberty, and 2.22 times more often in boys than girls. It is most frequently revealed during a routine pediatric examination, as well as when investigating the cause of abdominal pain and fever. A significantly higher level of serum bilirubin in boys as related to girls is registered only after a hypocaloric diet in age group between 16 and 18 years. .

Effect of bilirubin UDP glucuronosyltransferase 1 gene TATA box genotypes on serum bilirubin concentrations in chronic liver injuries

TATA box abnormality in the promoter region of the bilirubin UDP glucuronosyltransferase 1 gene has been reported to cause Gilbert's syndrome in white subjects. It has also been reported that the majority of Japanese patients with Gilbert's syndrome are heterozygous for Gly71Arg in the coding region of this gene. On the other hand, some patients with chronic hepatitis often show signs of unexpected hyperbilirubinemia. The aims of this study were to determine which of the genetic variations, TATA box genotype or codon 71 genotype, is most closely related to serum bilirubin concentrations, and whether the TATA box genotype has an effect on serum bilirubin concentrations in patients with hepatitis C-associated chronic liver diseases. In a sample of 300 individuals selected from among the general Japanese population, mean concentrations of total serum bilirubin differed significantly among TATA box genotypes, but not among codon 71 genotypes. Concentration of total serum bilirubin was significantly correlated with TATA box genotypes. In 211 patients with hepatitis C-associated chronic liver diseases, mean concentrations of total serum bilirubin also differed significantly among TATA box genotypes. In patients with chronic hepatitis C, concentration of total serum bilirubin was significantly correlated with TATA box genotypes. In summary, TATA box genotypes, but not codon 71 genotypes, are closely related to serum bilirubin concentrations. TATA box genotypes should therefore be considered when evaluating hepatic function by serum bilirubin concentrations in cases of hepatitis C-associated chronic liver diseases.

The hereditary hyperbilirubinaemias

The presence of jaundice in the neonate, infant or young child presents a broad differential diagnosis. The 'disease' may be benign, as in breast-milk jaundice, or potentially fatal, as in hereditary fructose intolerance. The cause of the jaundice may be a primary hepatic disorder, such as extrahepatic biliary atresia, or secondary to a non-hepatic cause, such as haemolysis or sepsis. There may be significant hepatic injury and dysfunction, as in fulminant viral hepatitis, or simply elevation of plasma bilirubin, as in Gilbert's syndrome. In this chapter we will discuss the familial hyperbilirubinaemia syndromes. This diverse group of disorders is characterized by hepatic dysfunction in the absence of hepatocellular injury. The first section of the chapter will discuss the unconjugated hyperbilirubinaemias: Crigler-Najjar syndrome I, Crigler-Najjar syndrome II and Gilbert's syndrome. The discovery of the gene for bilirubin uridine diphosphate glucuronosyltransferase has increased our understanding of the genetic heterogeneity and clinical presentation of the Crigler-Najjar syndromes. The remainder of the chapter will discuss the conjugated hyper-bilirubinemias: Rotor syndrome and Dubin-Johnson syndrome. These rare diseases share many clinical features; however, they can be readily distinguished by biochemical markers in the urine and bile.

Icteric plasma suggests Gilbert's syndrome in the blood donor

BACKGROUND

In a recent quality assurance audit of component returns over a 6-month period, 9 of 81 returns were due to icteric plasma. With the sensitive, new methods used to screen donors for anemia and hepatitis, it seemed likely that the icteric discoloration reflected benign unconjugated hyperbilirubinemia (Gilbert's syndrome) in the donor, rather than liver disease or hemolysis. The donors were recalled for repeat blood study to resolve this question.

STUDY DESIGN AND METHODS

Seven of the nine donors could be reached, and they submitted blood samples for measurement of serum levels of conjugated (direct-reacting) and total bilirubin and for complete blood and reticulocyte counts.

RESULTS

All seven donors had mild unconjugated hyperbilirubinemia, with total bilirubin levels ranging from 1.3 to 2.8 mg per dL. None showed evidence of overt hemolysis.

CONCLUSION

All seven donors of the components with icteric plasma have Gilbert's syndrome, a benign genetic anomaly occurring in approximately 3 to 5 percent of the general population. With the sensitive screening tests for viral hepatitis used today, the presence of icteric plasma in a component suggests that the donor has Gilbert's syndrome. Policies about the acceptability of icteric components from blood donors merit reassessment.